Price listed is for 3 grams of metal stones. There are about 20 stones in each 3 grams. These appear to be matte black plated. We believe these are aluminum. They measure about 14mm in diameter and about 4mm high. They have smooth domed tops and recessed backs. They were originally used for tops of metal buttons. Though we try to ensure quality, you may receive some that are dented, but they can easily be reshaped.